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QQ 5 m mNN 2 Sheets-Sheet 1.

Patentd Aug. 26, 1890.

J. PRULIOH.

ROCK DRILL (No Model.)

2 Sheets-Sheet 2.. J. FROLIOI-I.

ROCK DRILL (No Model.)

Patented Aug. 26, 1890.

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UNITED STATES PATENT OFFICE.

JULlUS FROLIOH, OF BARMEN, GERMANY.

ROCK-DRILL.

SPECIFICATION forming part of Letters Patent No. 435,139, dated August 26, 1890. Application filed June 3,1839. Serial No. 313,583. (No model.)

To all whom it may concern.-

Be it known that I, JULIUS FRGLICH, a subject of the King of Prussia, residing at Barmen, inthe Kingdom of Prussia, German Empire, have invented new and useful Improvements in Roek-Drills, of which the following is a specification.

My invention relates to improvements in rock-drills actuated by compressed air or by steam, and particularly in the reversing and propelling mechanisms of such machines, the former consisting of a hollow-cylinder valve moving within certain limits in an annular space of the striking-piston, while the latter consistsof a cylinder provided with a lateral passage and a regulating-cock, in which cylinder is arranged a braking apparatus composed of a piston firmly connected with the cylinder of the rock-drill, a brake-cylinder, rollers, brake-blocks, and of india-rubber or steel springs.

The improved rock-drill is illustrated in the accompanying drawings. Figure 1 is a longitudinal section of the rock-drill. Fig. 2 is a cross-section on line'A B of Fig. 1. Fig. 3 is a cross-section on line CD of Fig. 1. Figs. 4, 5, and 6 show modified constructions of the propelling mechanism.

The rock-drill consists of a long hollow cylinder a, in which fits in an air-tight manner and slides the true cylinderb of the drillingengine. In the latter is working the strikingpiston c, terminated by a hollow piston-rod cl, with the distributing-cylinder f arranged in an annular space of piston c. The outer cylinder-valve is closed at its rear end by a plug g, while the piston-rod (Z of the rock-drill extends through the fore end of cylinder (6. The fore part of cylinder a communicates through the port h with the compressed-air conduit,

while the fore and rear hollow spaces of the.

cylinder communicate with each other through a passage 2'. The passage 1' has a cock 7.;, by

means of whioh,on one hand, compressed air is led into the rear spaces of the cylinder a, and, on the other hand, by turning the said cock the rear space can be put in communication with the atmosphere, whereby the cylinderb can at will be moved forward or backward, which motions are regulated by an automatically-acting braking apparatus. The

latter consists of a piston Z, firmly connected with the cylinder 1) of the rock-drill and arranged in a cylinder in, movable thereon. The cylinder 12?. is furnished at its frontend wit-h a fiange,serving as an abutment for the rollers 0, arranged around the cylinder and pressed forward by an india-rubber or spring buffer p. Round the rollers o are arranged brake-blocks q,which are pressed by the rollers against the inner surface of cylinder to.

The operation of the machine is as follows: The compressed air entering the cylinder a through the port h passes through the front hollow space between the annular projection r of the cylinder 1) and the piston-rod to the inlet-passage s and thence through the passage s in the distributing-eylinder valve fand the passage 8 to the back of the piston 0, driving the latter forward until the boringtool, which is firmly connected with the piston-rod, strikes against the rock and stops the piston. The energy stored up in the distributing-cylinder valve causes the latter to move forward in such a manner that it closes the inlet passage s and opens the outlet-pas sages t 15, whereby the piston is moved backward. The compressed air behind the striking-piston escapes through the passage 8 the annular hollow space formed in the distributing-cylinder valve f, the outlet-passages t t into the hollow piston-rod, and thence into the open air. As soon as the piston at itsreturn-stroke has arrived at the recess a, formed in the cylinder 1), compressed air enters through port v, recess u, and passage in front of the distributing-cylinder valve, pushing the latter back into its initial position, whereupon the piston moves again forward. A small aperture 0: serves for permitting the escape at the forward stroke of the piston of the compressed air contained in the annular space in front of the distribnting-cylinder valve into the outlet-passages t t. In the beginning of the work the cock 7c is firstturned in such a manner that the rear hollow space of the cylinder at communicates with the outer air. The cylinder 1) and in consequence the piston c are pressed back by the additional pressure in the fore hollow space of the cylinder 66 against the plug g, whereupon the fore and rear parts of the cylinder a are put in communication again with each other by turning the cook it. The cylinder b, with the piston 0, would now at once be pushed forward up to the fore stuffing-box, owing to the additional pressure in the rear hollow space, unless it be held in its position by the braking apparatus which is connected with the rear cover 3 of the cylinder of the rock-drill. This is effected in the following way: At the return-stroke of the piston the space of the cylinder m communicates through passage z with the rear space of cylinder b, and consequently with the open air. Owing to the high air-pressure in the cylinder a, the cylinder m moves toward piston Z, the buffers 19 press the rollers 0 forward, and force the brake-blocks, owing to the inclined surfaces of the latter, against thewalls of cylinder a, holding thus the cylinder 1) in its position. At the forward stroke of the piston a compressed air enters through passage 2 into the cylinder m, removing the latter from piston I, while the brake is held in sufficient tension by the spring-buffers p for preventing the machine from moving forward. \Vhen the piston makes the longest desired stroke, the piston c strikes then against the ring r of cylinder 1), and the latter is taken along by the piston- 5. e., the forward stroke takes place and this until the machine is reversed and the brake at the return-stroke of piston c is applied again in the above-described manner.

In some cases the spring-power will not be sufficient to hold, at the forward stroke of the piston, the brake in, sufficient tension for preventing cylinder b from moving in cylinder at. In such cases I make use of the modified construction illustrated in Fig. 4.

A valve (1 is arranged here in the piston Z, preventing compressed air from entering cylinder m through passage 2'. The brake remains then applied until the piston 0 makes its longest stroke and the compressed air at the back of the piston can pass through passage b into the space of cylinder m. The

brake may be applied or taken off also by means of a differential piston 0, (see Fig. 5,) the larger area of which enters at the longest stroke through the passage 1) in communication with the compressed air, lifts the piston c, and thus takes off the brake until compressed air passes through passage 01', and also into the smaller space of the cylinder. After the machine has been reversed the two cylinder-halves enter in communication with the exterior atmosphere and the brake is put on, owing to the additional pressure on the smaller area f of the piston.

Instead of the rollers 0 flat wedge-pieces g, (see Fig. 5,) or dissimilar levers, such as h in Fig. 6, may be applied, which operate the brake-blocks in the same manner.

Having now fully described and ascertained the nature of my said invention and in what manner the same may be performed, I declare that whatl claim is-- l. A rock-drill actuated by means of compressed air or steam, consisting of a hollowcylinder valve f, moving in an annular space, of the striking-piston c, and of the necessary inlet and outlet passages 8 s and it, in combination with a propelling mechanism consisting of a hollow cylinder 0;, having alateral longitudinal passage 1' and a regulating-cock 71" and of a self-actin g braking apparatus, substantially as described, and shown in the drawings.

2. In rock-drills actuated by means of compressed air or steam, the combination of a hollow-cylinder valve f, furnished with a passage s and movable within certain limits in the annular space of the striking piston c, in combination with the inlet and outlet passages s s and t t, and with the recess 10, arranged in the cylinder Z) and serving to reverse the engine, the said recess having a port 42 and a passagew,substantiallyas set-forth,andshown in the drawings.

3. In rock-drills actuated by means of compressed air or steam, the combination of a hollow cylinder a, provided with a lateral passage c and a regulating-cock k, in which cylinder the boring-machine itself is contained, in combination with a self-actin g braking apparatus firmly connected with the cylinder b and consisting of the piston Z, the cylinder m, communicating through passage 2 with the rear space of the boring-cylinder b, the rollers 0, the brake-blocks q, and the shoulder r or passage 12', substantially as set forth, and shown in the drawings.

4. In a propelling mechanism for rock-drills, a self-acting braking apparatus consisting of the piston l, with valve a, cylinder m, with passage .2, rollers 0, and brake-blocks q, substantially as set forth, and shown in the drawings.

5. In a propelling mechanism for rock-drills, a self-acting braking apparatus consisting of the differential piston c, with valve a and passage (1, cylinder m, with passage 2, wedgepieces g or dissimilar levers h, substantially as set forth, and shown in the drawings.

In testimony whereof I have signed my name to this specification in the presence .of two subscribing witnesses.

JULIUS FROLICII.

Witnesses ZURMANN KOEPPEN, CARL WIECHMANN. 

